Numerous processes, especially in the field of pyrometallurgy, require the reaction of solid particulate material and a gas within an enclosure at elevated temperatures. Means for introducing suspensions of such particulate matter and gas have been previously proposed, but problems remain as to the means for such introduction into a highly heated atmosphere such that maximum gas-solid contact can be effected. In such processes, satisfactory contact of the particulate material and the gas is required during the brief exposure to the hot atmosphere, so as to provide adequate reaction rates.
An example of the type of processes to which the present means for introducing a particulate material and gas and the present method are directed is in the flash smelting of sulfide ores. Such a process requires that the solid sulfide ore particles and oxygen-containing gas be intimately mixed and that reaction of the two additives be effected rapidly. If such sulfides are flash smelted in a reverberatory furnace, for example, the distance between the roof of the furnace and the molten material in the furnace is usually less than 3 meters. Thus, the solid sulfide and oxygen-containing gas must be charged through the roof of the furnace by burners that will spread the material and form well dispersed suspensions that give intimate gas-solid-liquid contact and optimize interphase heat and mass transfer prior to the material reaching the molten bath.
A means for forming a paraboloidal suspension of a powdery substance and a reaction gas in a reaction space is disclosed in U.S. Pat. No. 4,147,535, utilizing the falling motion energy of solid matter and a specifically designed deflecting surface, optionally with horizontal jets of supplemental gas assisting in the spreading of the solid matter. The process and apparatus therein disclosed utilize the kinetic energy of the solids, and by use of the specified sliding surface, the powdery substance spreads laterally and meets the reaction gas flow substantially at right angles thereto in the reaction space.
In the present apparatus and process, a tangential introduction of a gas is effected, such that solids emitting from an inner tubular member are entrained by the circulating flow of gases and discharged from an outer cylindroidal member at a tangential spreading velocity greater than one-half the vertical downward velocity thereof, with a paraboloidal suspension formed in the reactor.